To beat a level you must kill all enemies. To kill enemy you must first bubble it and then burst the bubble by touching it. If you are too slow bubble burst itself and enemy gets back out. It might be little angrier after unpleasant bubbling experience.
There is some platforms that are to high to jump on?
True. But you can jump on top of your on balloons. So just shoot a bubble from right place and run/jump to top of it, and from there try to jump to the platform.
This game is way too hard?
Not true. Use time, be patient. There is no rush. You have plenty of time before those creepy HurryUppers arrive.